2-[4-(2-pyridinyloxy)phenoxy]propionyl-2-oxazolidinones

ABSTRACT

The subject matter of this invention involves 2-[4-(2-pyridinyloxy)phenoxy]propionyl-2-oxazolidinones which are substituted in the pyridinyl ring by trifluoromethyl and/or chloro. The compounds are useful for increasing the recoverable sugar in sugarcane.

This application is a continuation-in-part of application Ser. No. 766,730, filed Aug. 19, 1985, now abandoned.

This invention relates to 2-[4-(2-pyridinyloxy)phenoxy]propionyl-2-oxazolidinones and to be a method of increasing the yield of sugar obtained from sugarcane and more particularly relates to a method of increasing the recoverable sugar in sugarcane by treating the sugarcane plant during its maturation with said compounds.

A variety of plant growth regulators, stimulants and promoters have been tried in the past in attempts to increase the yields of cultivated crops. It has been found that materials that have an effect on one crop will not necessarily have an effect or have a different effect on other crops.

It has now been found that the recovery of sugar from sugarcane can be significantly increased by the use of certain esters. Consequently it has now been found that it is possible to increase the recoverable sugar in sugarcane by contacting the sugarcane plant with an effective amount of a compound of the formula I: ##STR1## wherein X is chloro or trifluoromethyl, and Y is hydrogen or chloro.

The compounds of the formula I can readily be prepared by reacting the corresponding 2-[4-(2-pyridinyloxy)phenoxy]propionic acid chloride and 2-oxazolidinone as illustrated in the following Example 1.

EXAMPLE 1 Preparation of 2-[4-(5-trifluoromethyl-2-pyridinyloxy)phenoxy]propionyl-2-oxazolidinone

2-[4-(5-Trifluoromethyl-2-pyridinyloxy)phenoxy]propionic acid (3.7 gram; 0.01128 mol) and thionyl chloride (15 ml) were placed into a 50 ml. round bottomed glass reaction flask equipped with stirrer, condenser, thermometer, and a nitrogen line. This reaction mixture was stirred for 11/4 hours at 70° C., cooled and stripped yielding the desired acidchloride.

2-Oxazolidone (1.5 grams; 0.017 mol), dichloromethane (90 ml), and triethylamine (5 ml) were placed into a 3-necked glass reaction flask equipped with stirrer, reflux condenser and thermometer. This mixture was cooled to 10° C. 2-[4-(5-Trifluoromethyl-2-pyridinyloxy)phenoxy]propionic acid chloride (5.7 grams; 0.016 mol) in dichloromethane (30 ml.) was added to the cooledmixture which was then stirred for 3 hours at room temperature. This product mixture was washed with water (60 ml.) and (5%) sodium bicarbonate(70 ml) and concentrated to yield an orange gum (6.9 grams) which was dissolved in hot tuluene, treated with Nuchar charcoal, filtered, and concentrated. The residue was recrystallized from a mixture of dichloromethane and hexane leaving a white solid (3.3 grams), melting point 101°-102° C. Elemental analysis for the desired product was as follows:

    ______________________________________                                                       Theoretical                                                                            Found                                                    ______________________________________                                         Carbon          54.55     54.56                                                Hydrogen        3.82      3.88                                                 Nitrogen        7.07      6.98                                                 ______________________________________                                    

Infrared analysis was consistent with the product, 2-[4-5-trifluoromethyl-2-pyridinyloxy)phenoxy]propionyl-2-oxazolidinone.

The effectiveness of the compounds of the formula I for increasing the recoverable sugar in sugarcane is demonstrated by the following three tests. The cane was harvested eight weeks after application of the compound.

The top 14 joints of the treated cane as well as those of the controls wereremoved, combined and analyzed for juice purity and pol percent cane, following the "press method" developed and described by T. Tanimoto, Hawaiian Planters Record, 57, 133 (1964). Pol percent cane is a polarimetric determination and equals the percentage of sucrose if the latter is the only substance in the solution which will rotate the plane of polarized light. The pol percent cane is a standard method of determining the sucrose content of sugarcane.

    ______________________________________                                                  Rate of                                                                        Application Pol %   Juice                                                      (lbs./acre) Cane    Purity                                            ______________________________________                                         TEST 1                                                                         Compound of                                                                               1             15.12   86.83                                         Example 1                                                                      Control    0             10.06   76.54                                         TEST 2                                                                         Compound of                                                                               1             14.91   85.91                                         Example 1                                                                      Control    0             11.61   80.66                                         TEST 3                                                                         Compound of                                                                               1             12.51   83.57                                         Example 1  0.5           12.21   83.66                                         Control    0             10.78   81.76                                         ______________________________________                                    

In the use of the compounds of the formula I to increase the recoverable sugar in sugarcane, sugarcane is treated at a late stage of development ofthe sugarcane wherein most of the sugar formation takes place. Thus, under normal growing conditions and common cultivation practices the active compounds of this invention can be applied to the sugarcane during the period of from about 2 to about 10 weeks before harvesting.

The amount of the compound of the formula I required to effectively increase the recoverable sugar from sugarcane can vary somewhat depending on such factors as the time of application, the weather, crop density, method of application and the like. Generally, an amount of at least 0.1 pounds per acre and preferably an amount of from 0.1 pounds per acre to about 10 pounds per acre can be used. While an amount greater than those mentioned can be used, they will not result in an advantage that would warrant their expense and are, therefore, not practical.

For practical use in treating sugarcane, the active compounds of this invention are generally incorporated into compositions or formulations which comprise an inert carrier and an effective amount of the compound. The compositions enable the active compound to be conveniently applied to the sugarcane at the desired rate. The formulations can be liquid formulations such as emulsifiable concentrates or solutions or solid formulations such as dusts, granules or wettable powders.

The preferred compositions are liquid formulations, particularly solutions or emulsifiable concentrates. Emulsifiable concentrates comprise a compound of the formula I, according to this invention, and as the inert carrier, a solvent and an emulsifier. Such emulsifiable concentrates can be extended with water and/or oil to any desired concentration of active compound for application as sprays to the sugarcane. The emulsifier most commonly used in these concentrates are nonionic or mixtures of nonionic with anionic surface-active agents. With the use of some emulsifier systems an inverted emulsion (water-in-oil) can be prepared.

Typical formulations according to the present invention useful for increasing the recoverable sugar in sugarcane are illustrated in the following examples wherein the quantities are given in parts by weight.

EXAMPLE 2 Preparation of an Emulsifiable Concentrate

The following ingredients are blended thoroughly until a homogeneous liquidconcentrate is obtained. This concentrate is mixed with water to give an aqueous dispersion containing the desired concentration of the active ingredients for use as a spray.

    ______________________________________                                         Product of EXAMPLE 1                                                                               25                                                         Sodium lauryl sulfate                                                                               2                                                         Sodium lignin sulfate                                                                               3                                                         Kerosene            70                                                         ______________________________________                                    

EXAMPLE 3 Preparation of a Wettable Powder

The following components are mixed intimately in conventional mixing or blending equipment and are then ground to a powder having a particle size of less than about 50 microns. The finished powder is dispersed in water to give the desired concentration of active compound for application to the sugarcane.

    ______________________________________                                         Product of EXAMPLE 1                                                                               50                                                         Fuller's earth      47                                                         Sodium lauryl sulfate                                                                              2.5                                                        Methyl cellulose    0.5                                                        ______________________________________                                    

EXAMPLE 4 Preparation of a Dust

The following ingredients are mixed thoroughly and are then ground to an average particle size of less than about 50 microns to give a dust suitable for application with conventional dusting equipment.

    ______________________________________                                         Product of EXAMPLE 1                                                                               10                                                         Powdered talc       90                                                         ______________________________________                                    

The effectiveness of the compounds of this invention for increasing the recoverable sugar from sugarcane was demonstrated in a field test by applying a solution in acetone diluted for application to the various indicated application rates. The test compound of Example 1 was applied ateach rate on the spindle area of each of 20 stalks of sugarcane in a field in Hawaii, using a syringe with a fine needle as the applicator. A set of 10 these stalks from each group was harvested at 4 and 8 weeks after such treatment. In each harvest a set of 10 untreated stalks were also harvested as a control. 

We claim:
 1. A compound of the formula: ##STR2## wherein X is chloro or trifluoromethyl, and Y is hydrogen or chloro.
 2. The compound of claim 1 in which X is trifluoromethyl and Y is hydrogen.
 3. A method for increasing the recoverable sugar contained in sugarcane which comprises contacting the sugarcane plant with an effective amount of a compound of claim
 1. 4. The method of claim 3 wherein the sugarcane is contacted with from about 0.1 to about 10 pounds of the compound of claim
 1. 5. The method of claim 3 wherein the sugarcane plant is contacted with the compound from about 2 to about 10 weeks before harvest.
 6. The method of claim 4 wherein the sugarcane plant is contacted with the compound from about 2 to about 10 weeks before harvest.
 7. The method of claim 5 wherein X is trifluoromethyl and Y is hydrogen. 